[Alumnos] CHARLA PROFESOR VISITANTE

[Alejandro Corsico]

Estimados Docentes-Investigadores, Graduados y Alumnos:  

 	El próximo martes 15 de octubre a las 15:00 hs brindará una 
conferencia el Profesor Enrique García-Berro del Departamento de Física 
Aplicada de la Universidad Politécnica de Cataluña, Castelldefels, España, 
quien se encontrará visitando la Facultad.                 

 	La conferencia se titula: "High resolution simulations of white 
dwarf collisions"

 	Abstract: In old, dense stellar systems collisions of white dwarfs 
are a rather frequent phenomenon.  I will present the results of a 
comprehensive set of Smoothed Particle Hydrodynamics simulations of close 
encounters of white dwarfs aimed to explore the outcome of the interaction 
and the nature of the final remnants for different initial conditions. 
Depending on the initial conditions and the white dwarf masses, three 
different outcomes are possible.  Specifically, the outcome of the 
interaction can be either a direct or a lateral collision or the 
interaction can result in the formation of an eccentric binary system. In 
those cases in which a collision occurs, the infalling material is 
compressed and heated such that the physical conditions for a detonation 
may be reached during the most violent phases of the merger.  While we 
find that detonations occur in a significant number of our simulations, in 
some of them the temperature increase in the shocked region rapidly lifts 
degeneracy, leading to the quenching of the burning.  We thus characterize 
under which circumstances a detonation is likely to occur as a result of 
the impact of the disrupted star on the surface of the more massive white 
dwarf. Finally, we also study which interactions result in bound systems, 
and in which ones the more massive white dwarf is also disrupted as a 
consequence of the dynamical interaction.  The sizable number of 
simulations performed in this work allows to find how the outcome of the 
interaction depends on the distance at closest approach, and on the masses 
of the colliding white dwarfs, and which is the chemical pattern of the 
nuclearly processed material.  Finally, we also discuss the influence of 
the masses and core chemical compositions of the interacting white dwarfs 
and the different kinds of impact in the properties of the remnants.

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Alejandro H. Córsico
Doctor en Astronomía
Facultad de Ciencias Astronómicas y Geofísicas
UNIVERSIDAD NACIONAL DE LA PLATA

Observatorio - Paseo del Bosque S/N
B1900FWA La Plata, Argentina
Phone:             +54-221-423-6593
Fax:               +54-221-423-6591
E-Mail: acorsico en fcaglp.unlp.edu.ar
WWW: http://www.fcaglp.unlp.edu.ar/evolgroup/alejandro.html
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